A fourth person was hurt but did not require treatment at a hospital.... Among them was Justin Rockhold, whose ninth-grade son had texted to let him know he was OK. Rockhold said he has served in the military and he drew on that experience to instruct his son, telling him to keep his head down and be still to stay safe.... When asked whether he had thought a shooting could happen at the school, he said his military training is also a reminder of life’s dangerous realities.“ Obviously in Americ